audio file won't upload

I have a GP site at http://quinn.michianait.net. I have two audio files I would like to use on the website. one is called "Vainement, ma bien-aimée.mp3" and the other is In der Frühe - Hugo Wolf.wav. The .wav file uploads to the media library, but the .mp3 file throws an error saying that for security reason this type of file is not allowed.

They both seem like pretty standard file types. Is there a setting I have to make to allow file uploads for both types?

Thanks

Mark